UN: Concentrations of greenhouse gases hit record

By the Associated Press | November 21, 2011 | 5:05 AM EST

FILE - In this July 19, 2011 file photograph, Indian army soldiers returning from border posts get a briefing at the Siachen Glacier base camp, in Indian Kashmir on the border with Pakistan. Four Himalayan nations, faced with erratic weather and the threat of melting glaciers and catastrophic floods, are hashing out a plan for preserving the vast mountain range and helping millions living in the foothills cope with climate change. (AP Photo/Channi Anand)

The World Meteorological Organization says heat-trapping carbon dioxide concentrations in the air have reached 389 parts per million — the highest such concentrations since the start of the industrial era in 1750.